So I completely rebuilt my 4.6 for my DII (with help from some excellent professional Porsche guys that really know their ****- I only sort of know what I"m doing) and I"m now on my 3rd timing cover/ oil pump- finally making really good oil pressure (* 50LBS when cold- down to around 30lbs once warmed up- never seems to go below 30) because after the build I had an oil light come on and was getting no oil pressure after about a month of driving. I replaced the timing cover and have all new gears (twice- seems like the quality of the products out there is just worse and worse) replacing it with a genuine ($$$$) Land Rover cover.

After the cover was replaced and I finally got good oil pressure my harmonic balancer was compromised- the rubber in the center was dry rotted (?) and the two sections would spin independently- so now that's replaced as well. After all this- now I have a terrible valve train ticking/knocking. This is a top-hat sleeved motor and I spent all that money to get RID of ticking- and now it's back.

I have great oil pressure- where should I start to check to see what the hell is making all this noise. It sounds like it's on the drivers side towards the firewall- and it sounds like a bad lifter or valve- I'm trying to figure out post rebuild what the actual oil path is in these things to get the oil up there. It sounds like it's not getting oil to the back of the valve train- that's where I'm starting in frustration

Any guidance on where to start? I should add- it gets worse as the engine warms up- it's almost not audible when cold- but once the engine is at operating temps it's loud. Also- it's louder from down below near the bell housing and case joining- but that could be acoustics- it's a lower pitch down there too- but still pretty loud at the back of the valve covers. ¯\_(ツ)_/¯

 

OIl pressure, it drops as the engine warms up, how are you checking your oil pressure. I get about 18 at idle and mid 40s at 2500 rpm HOT. (10/40) After 2 timing covers my bet is you had or have a clog, so your oil passages may be gummed up the pick tube may be partly blocked.

But you can pull the valve covers and manually check the rockers, for broken springs, "loose" pushrods, valve springs too
If there is nothing obvious pull the rockers and and inspect for wear
If that does not show any evidence of a problem you can try an old school test leave the valve covers off put everything else back in place, add some cardboard to control oil splatter and start it up watch the rocker and and pushrods see if anything is sticking and possibly identify the problem area
If all that comes back clean, you will need to get the bottom end checked

 

Thanks- that helps. I'm checking the oil pressure with a pressure gauge plugged into the oil pressure sensor port. I did put some MOA in it and it did lessen it a bit- which makes me think you're on to something with a clogs passage from the previous oil pump problems- it didn't solve it- but it helped. Should I drain the oil entirely- refresh and add more MOA to maybe clean things out?
My "Porsche" mechanic thought the MOA was snake oil at this point since it's a fresh build on only one oil change- but he doesn't know how quickly things can go wrong with a Rover! I hate this motor- it's been nothing but one problem after another and on my build I said if I had to pull the motor out again an LS was going back in with a 6L80. Starting to seriously save for that eventuality.

 

Did you use new or rebuilt hydraulic lifters? My engine that broke suddenly (probably a cracked liner or block) and had the typical D2 knock. I took it apart recently and couldn't see any potential cause for the knocking than completely stuck lifters. No shifted or lose liners, crankshaft bearings OK, connecting rod bearings with typical wear.

 

Because you did a recent rebuild I am suspecting the rocker shafts. It is possible to put then on upside down and still have good oil pressure, but if you do the top end will not be lubricated correctly and will tick (ask me how I know). Check that. Also, bell housing tick could be a broken flex plate, but since you pulled the motor I am assuming that was checked and had no cracks. You could remove the torque converter bolts and start it and see if it ticks without spinning the torque converter.

What is your oil pressure hot, idling?

 

Rebuilt lifters- with proper lifter lash adjusted correctly.

 

I would think rocker shafts installed upside down would be a problem right away. This is around 6 months of driving that it started- one full oil change after inital break in at 500 miles- I have less then 1500 miles on the motor now- but had a TON of problems with bad oil pumps- I'm on number 3 I think. But it was running fine and quiet until the pump went bad- then I installed a new one that was bad out of the gate- and finally installed another (OEM) that seem fine. Oil pressure at idle is around 20- 28 lbs- then when off-idle all the way up to 50lbs- so decent oil pressure. I thought for sure I had another bad oil pump- but the pressure measured at the sensor is terrific now.

I'll get the rig into the shop next weekend and probably pull the valve covers off- put everything back together and see if I"m getting oil at the top end. What at PITA these engines are- I should have to do ANY of this post rebuild. The parts supplied anymore are just CRAP!

 

Very frustrating for sure. The quality of parts available is 100% a major concern these days. Generally though very simple motors that run pretty well (running well and generating power are different lol).

 

When you rebuilt your engine, did you check for slipped liners? I found an imprint from what looks like a moving liner of cyl #4 on the head gasket. Since I had the typical knocking and this cylinder caused the engine to fail I believe it was indeed a slipped liner.

 

@Discorama top hatted block so that is pretty unlikely, my gut is rockers or lifters oil pressure light on is always bad